In three-dimensional (3D) computer graphics, a depth map is an image or an image channel that contains information relating to a distance of surfaces of scene objects from a viewpoint. The term is related to and may be analogous to a depth buffer, a Z-buffer, Z-buffering, a Z-depth and disparity. The term “Z” relates to a convention that the central axis of view of a camera is in the direction of the camera's Z axis, and not to the absolute Z axis of a scene.
Such depth map is an addition to the main image, typically a stereo pair, and needs to be usually generated from the stereo pair. The quality of this generation process in the end influences the users' perception of depth in cases where original stereo pair is blended with further graphical data such as on-screen display menus or video effects.
It would be thus advantageous to define a method of generating depth map, from a pair of stereoscopic images, with a simultaneous verification of the reliability of the determined disparity.